99 5.4 computer or transmission problem
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Joined: May 2011
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99 5.4 computer or transmission problem
While driving at 65 mph, I had the check engine light come on and the truck started shifting in and out of gear. The theft light would flash as it did this and all the gauges would bounce back and forth. I was able to limp it home with it doing this every couple miles. It didnt matter what gear I put the transmission in. Anybody have anything like this happen before? It is a 99 F150 with 5.4 and series M Transmission. 122,000 miles on it. Any help or suggestions?
Born to a Ford Family
Joined: Nov 2010
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From: Beavercreek, OH
More info please. When you say shifting in an out of gear, do you mean bouncing back and forth between Drive and OD? Did the tach bounce UP with the "in and out"? Did all Gauges bounce (gas, temp, Oil, tach) or just tach and oil? Did the CEL illuminate at all?
Thread Starter
Junior Member
Joined: May 2011
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The tach and spedo would bounce from to zero to wide open, the theft light would flash and the truck would downshift or lose power. It didnt matter whether it was 2, 3, or OD. I drove it go 45 miles back home with it doing this every couple miles. It died twice when I let off the gas. It would start right up after it died. When it wasn't doing this it would drive just fine.